I had this happen several times on my old KitchenAid smoothtop. It is either the burner element or the switch to the element.

Either way you will have to have it serviced. The element is about $100 for the part and a switch could be about $50 for the part.

If you are handy with tools and have a multi-meter you can check the switch yourself. Of course if you are going to tool around near 220v better unplug the thing. 220v in the right place can kill you.

Here is a link that might be useful: Test an Infinite Switch

Thanks for the helpful information.

There is a small indicator light between the knobs.It glows every time I turn the knob on and the surface element also glows. In this case when I turn the RightFront knob the indicator light beside it turns on but the surface element does not. My question is ,if the indicator light next to the knobs turns on, does it mean the infinite switch is getting electricity. ? Or should it be opened and tested with the ohm meter for accurate results.?

Thanks

The tech will use an ohm meter. Sounds to me like the element is the problem, not the switch.